Parathyroid Hormone: Uses, Side Effects, Dosage - Drugvu

ℹ️ Compiled from public regulatory records · Last regulator revision: May 15, 2026🚩 Report this page

Parathyroid Hormone

Parathyroid Hormones and Analogues

Sold as Natpar · Preotact

GB MHRAEU EMA

Drug class: Parathyroid Hormones and Analogues
Availability: See label
Markets covered: 2
Products on record: 5

Overview

Parathyroid Hormone is an active pharmaceutical ingredient in the Parathyroid Hormones and Analogues group (H05AA). The information below is compiled per regulator from the product labels on record, with direct links to the original documents.

Regulatory status by market

Market	Regulator	Products	Last revision
GB United Kingdom	MHRA	4	May 15, 2026
EU European Union	EMA	1	July 15, 2025

GBUnited Kingdom· MHRA

4 products

Uses

GBOfficial regulatory label· revised January 9, 2026[1]

Natpar is indicated as adjunctive treatment of adult patients with chronic hypoparathyroidism who cannot be adequately controlled with standard therapy alone.

How to take

EUEuropean Union· EMA

1 product

Uses

EUOfficial regulatory label· revised July 15, 2025[2]

Natpar is indicated as adjunctive treatment of adult patients with chronic hypoparathyroidism who cannot be adequately controlled with standard therapy alone. 3

How to take

Drug interactions

Known interactions involving Parathyroid Hormone. Select one for details. This list is informational and not a complete interaction checker.

Digitoxin Digoxin Alendronate Calcitriol

Interaction data compiled from DDInter (academic, CC-BY). Severity classification only - this is not a complete interaction checker and not medical advice.

Sources & citations

[1]MHRA (UK) · PLGB549370010 · revised January 9, 2026
[2]European Medicines Agency · EMEA/H/C/003861 · revised July 15, 2025

Information on this page is compiled from public regulatory records. Drugvu is not affiliated with any regulator or pharmaceutical manufacturer. This is not medical advice. Always consult a qualified healthcare professional.

Side effects & warnings

GBOfficial regulatory label· Adverse reactions· revised January 9, 2026[1]

Summary of the safety profile The most frequent adverse reactions among patients treated with Natpar were hypercalcaemia, hypocalcaemia, and their associated clinical manifestations including headache, diarrhoea, vomiting, paraesthesia, hypoaesthesia and hypercalciuria.
1). Tabulated list of adverse reactions Adverse reactions for Natpar-treated patients in the placebo-controlled study and in post-marketing experience are listed below by MedDRA system organ class and frequency. Frequencies are defined as very common (≥1/10), common (≥1/100 to <1/10), and not known (cannot be estimated from the available data).
All adverse reactions identified in post-marketing experience are italicised. System organ class Very common (≥1/10) Common (≥1/100 to <1/10) Not known (cannot be estimated from the available data) Immune system dysorders Hypersensitivity reactions, (dyspnoea, angioedema, urticaria, rash) Metabolism and nutrition disorders hypercalcaemia, hypocalcaemia hypomagnesaemia†, tetany† Psychiatric disorders anxiety†, insomnia* Nervous system disorders headache*,†, hypoaesthesia†, paraesthesia† somnolence* Cardiac disorders palpitations*,† Vascular disorders hypertension* Respiratory, thoracic and mediastinal disorders cough† Gastrointestinal disorders diarrhoea*,†, nausea*, vomiting* abdominal pain upper* Musculoskeletal and connective tissue disorders arthralgia*, muscle spasms† muscle twitching†, musculoskeletal pain†, myalgia†, neck pain†, pain in extremity Renal and urinary disorders hypercalciuria*, pollakiuria† General disorders and administration site conditions asthenia*, chest pain†, fatigue, injection site reactions, thirst* Investigations anti-PTH antibody positive, blood 25-hydroxycholecalc iferol decreased†, vitamin D decreased *Signs and symptoms potentially associated with hypercalcaemia that were observed in the clinical trials.
†Signs and symptoms potentially associated with hypocalcaemia that were observed in the clinical trials. Description of selected adverse reactions Hypercalcaemia and hypocalcaemia were commonly encountered during the dose titration period.
The risk for serious hypocalcaemia was greatest after the withdrawal of Natpar. 4). 5% (8/84) Natpar-treated patients and 15% (6/40) placebo-treated patients experienced an injection site reaction, all of which were mild or moderate in severity.
Immunogenicity Consistent with the potentially immunogenic properties of medicinal products containing peptides, administration of Natpar may trigger the development of antibodies. 9% (1/17) in patients who received subcutaneous administration of 50 to 100 micrograms Natpar or placebo once daily for 24 weeks, respectively.
4%) and did not appear to increase over time. These 16 patients had low titre anti-PTH antibodies and, of these, 12 subsequently became antibody negative. The apparent transient nature of antibodies to PTH is likely due to the low titre.
Two of these patients had antibodies with neutralising activity; these patients maintained a clinical response with no evidence of immune-related adverse reactions. Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorisation of the medicinal product is important.
It allows continued monitoring of the benefit/risk balance of the medicinal product. uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.

GBOfficial regulatory label· Warnings and precautions· revised January 9, 2026[1]

Traceability In order to improve the traceability of biological medicinal products, the name and batch number of the administered product should be clearly recorded. 55 mmol/L. 2). 7 mmol/L. 2). Hypercalcaemia Hypercalcaemia was reported in clinical trials with Natpar.
Hypercalcaemia commonly occurred during the titration period, during which doses of oral calcium, active vitamin D, and Natpar were being adjusted. Hypercalcaemia may be minimised by following the recommended dosing, the monitoring information, and asking patients about any symptoms of hypercalcaemia.
0 mmol/L or above upper limit of normal with symptoms) develops, hydration and temporarily stopping Natpar, calcium and active vitamin D should be considered until serum calcium returns to the normal range. 8). Hypocalcaemia Hypocalcaemia, a common clinical manifestation of hypoparathyroidism, was reported in clinical trials with Natpar.
Most of the hypocalcaemic events occurring in the clinical trials were mild to moderate in severity. In the post-marketing setting, cases of symptomatic hypocalcaemia, including cases that resulted in seizures, have been reported in patients being treated with Natpar.
The risk for serious hypocalcaemia is highest after Natpar is withheld, missed or abruptly discontinued, but can occur at any time. Temporary or permanent discontinuation of Natpar must be accompanied by monitoring of serum calcium levels and increase of exogenous calcium and/or active vitamin D sources as necessary.
8). Concomitant use with cardiac glycosides Hypercalcaemia of any cause may predispose to digitalis toxicity. 5). Severe renal or hepatic disease Natpar should be used with caution in patients with severe renal or hepatic disease because they have not been evaluated in clinical trials.
3). Use in elderly patients Clinical studies of Natpar did not include sufficient numbers of subjects aged 65 and over to determine whether response in these subjects is different from younger subjects. Tachyphylaxis The calcium-raising effect of Natpar may diminish over time in some patients.
The response of serum calcium concentration to administration of Natpar should be monitored at intervals to detect this and the diagnosis of tachyphylaxis considered. 2). Urolithiasis Natpar has not been studied in patients with urolithiasis.

This is not medical advice. Consult a qualified healthcare professional.

General Treatment should be supervised by a physician or other qualified healthcare professional experienced in the management of patients with hypoparathyroidism. 4). The optimisation of parameters of calcium-phosphate metabolism should be in line with current therapeutic guidelines for the treatment of hypoparathyroidism.
Prior to initiating and during treatment with Natpar: • Confirm 25-OH vitamin D stores are sufficient. • Confirm serum magnesium is within the reference range. Posology Initiating Natpar 1. Initiate treatment with 50 micrograms once daily as a subcutaneous injection in the thigh (alternate thigh every day).
25 mmol/L, a starting dose of 25 micrograms can be considered. 2. 87 mmol/L. 3. In patients using calcium supplements, maintain calcium supplement dose. 4. Measure pre-dose serum calcium concentration within 2 to 5 days. 55 mmol/L, this measurement should be repeated the following day.
5. , signs and symptoms of hypocalcaemia or hypercalcaemia). Suggested adjustments to Natpar, active vitamin D and calcium supplements based on serum calcium levels are provided below: 6. 25 mmol/L, active vitamin D has been discontinued and calcium supplementation is sufficient to meet daily requirements.
4). The dose of Natpar may be increased by 25 microgram increments approximately every 2 to 4 weeks, up to a maximum daily dose of 100 micrograms. Downward titration to a minimum of 25 micrograms can occur at any time. It is recommended to measure the albumin-corrected serum calcium 8-12 hours after dosing Natpar.
If post-dose serum calcium is >ULN, then first reduce active vitamin D and calcium supplements and monitor progress. Measurements of pre- and post-dose serum calcium should be repeated and confirmed to be within an acceptable range before titration to a higher dose of Natpar is considered.
If post-dose serum calcium remains >ULN, oral calcium supplementation should be further reduced or discontinued (see also adjustment table under Initiating Natpar). 4). Missed dose In the case of a missed dose, Natpar must be administered as soon as reasonably feasible and additional exogenous sources of calcium and/or active vitamin D must be taken based on symptoms of hypocalcaemia.
Interruption or discontinuation of treatment Abrupt interruption or discontinuation of Natpar can result in severe hypocalcaemia. 4). 2. Renal impairment No dose adjustment is necessary in patients with mild to moderate renal impairment (creatinine clearance 30 to 80 mL/min).
4). Hepatic impairment No dose adjustment is necessary for patients with mild or moderate hepatic impairment (total score of 7 to 9 on the Child-Pugh scale). 4). Paediatric population The safety and efficacy of Natpar in children less than 18 years of age have not yet been established.
No data are available. Method of administration Natpar is suitable for patient self-administration. Patients must be trained on the proper injection techniques by the prescriber or nurse, in particular during initial use. Each dose must be administered as a subcutaneous injection once a day in alternating thighs.
6 and the instructions included with the package leaflet. Natpar must not be administered intravenously or intramuscularly. 5